This is a Tutorial on how to properly install CFW or LCFW 6.60 ME 1.8 on your PSP. This is for all PSP models 1000 through PSP Go. This is obviously not for the PS Vita.
PSP 1000, 2000 Install.
Download the 2379_release_660me_18 file from my list of the downloads and extract or open the files. When you open the file you should see a release_660me folder and if you open up that folder you will see an UPDATE, Translate and leda folder. Take the UPDATE folder and place that in the ms0:/PSP/GAME folder. Once you've done that take the leda folder and open it and you will see the leda.prx within it. On the ms0:/ root of the memory stick (MS), if you havent already create a folder called seplugins then open it. Put the leda.prx within this folder and then create a new text document and call it GAME.txt. Open it and inside write "ms0:/seplugins/leda.prx 1" with no quotes and than your done. Exit USB mode and run the installer and even if your on OFW it will flash install the Permanent patch cause its signed to work on OFW.
PSP 2000v2, 3000 and Go install.
Download the 2379_release_660lme_18 file from my list of downloads and extract or open the file. When you open the file you should see a release_660lme folder and in that forlder you will see a Translate, PSP and leda folder. In the leda folder you will find the leda.prx On the root of the MS create a folder, if you havent already called seplugins and open it. Place the leda.prx in this folder. Now create a GAME.txt document, if you havent already, and open it. If your using a MS inside write "ms0:/seplugins/leda.prx 1" no quotes and if your using the internal storage on a PSP Go write "ef0:/seplugins/leda.prx 1" no qoutes. Now in the extracted files go into the PSP folder and then the GAME folder and you will find a launcher and installer folder. These two folders take them and copy them to the ms0:/PSP/GAME or ef0:/PSP/GAME folder and then exit USB mode. On the PSP system run the Installer first and then once you get back to the XMB run the Launcher and your done.